Fix fields serialization

Change-Id: I717c7ccb7b9a58050636cae3c8a91bfcbd64e4fb
diff --git a/Changes b/Changes
index 5732d43..2dda6e1 100644
--- a/Changes
+++ b/Changes
@@ -17,6 +17,7 @@
 	- [bugfix] Fixed treatment of several collection types (diewald)
 	- [bugfix] Remove legacy error handling in Match (diewald)
 	- [bugfix] JSON-serialization bug in match in case of error messages (diewald)
+	- [bugfix] 'fields' serialization (diewald)
 
 0.51 2015-03-17
         - This is a major version (prepared for the GitHub release)